The present invention relates generally to process control systems and, more particularly, to the use of a portable computer to provide enhanced support within a process control environment.
Process control systems, like those used in chemical, petroleum or other processes, generally include a centralized process controller that is communicatively coupled to at least one host or operator workstation and to one or more field devices via analog, digital or combined analog/digital buses. The field devices, which may be, for example valves, valve positioners, switches, sensors (e.g., temperature, pressure and flow rate sensors), etc., perform control functions within the process such as opening or closing valves and taking measurements of process parameters. Generally speaking, the process controller receives signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals which are sent over the buses to the field devices to control the operation of the process. Information from the field devices and the controller is typically made available to one or more applications that are executed by the operator workstation to enable an operator to perform any desired function with respect to the process, such as viewing the current state of the process, modifying the operation of the process, performing diagnostic activities, optimizing the process, managing process alerts or alarms, carrying out batch activities, etc.
While an operator or a technician can access a variety of types of information pertaining to the process control system and the individual devices therein (such as help, diagnostic, set-up and configuration information) using the host or operator workstation, there are many process control activities that require a technician to go out into the actual plant environment where no host or operator workstation is present. Such activities include, for example, visually inspecting a process control device or area, connecting devices or buses within the process control environment, taking manual measurements, troubleshooting, repairing and replacing field devices, etc. In these cases, the operator or technician may carry manuals pertaining to the function to be performed out into the plant and look up any needed information in the field. This process can be very cumbersome. More likely, the technician will return to the operator workstation one or more times to look up any information he or she may need during the course of the performing the desired activity, which is very time consuming and prone to error. Other times, the technician will carry a radio or walkie-talkie into the plant and communicate via the radio with an operator located at the operator workstation to get any needed information. However, the amount of information that can be provided over the radio is limited and is prone to errors because it is based on human communications. Furthermore, because the technician typically carries and operates the radio using his or her hands, the use of a radio makes performing certain functions, like repairing a device, much more cumbersome and difficult.
With the advent of smaller electronics, portable computers in the form of wearable and/or hand-held computers have become more readily available. A wearable and/or hand-held computer generally includes a standard central processing unit (CPU) and a memory packaged in a small container that may be placed within a pouch on a belt or harness worn by a user (also referred to herein as a xe2x80x9cwearerxe2x80x9d) which is designed to make carrying the wearable computer as convenient as possible. In some cases, a hand-held computer such as, for example, a personal data assistant (PDA) may be hand carried, holstered in a belt or pouch, or otherwise worn by a user as needed or desired. By way of example, a user may holster (i.e., wear) a PDA while in transit to a particular location within a process plant and, upon arriving at that location, may remove the PDA from the holster and begin to use the PDA as a hand-held computer. Batteries for powering a wearable and/or hand-held computer may be located in a different pouch within a harness or within an integral compartment of the computer housing. Peripheral devices, such as disk drives, hard drives, PCMCIA slots, microphones, bar code readers and keyboard devices may be communicatively coupled to the CPU via appropriate wires or buses and, if desired, one or more of these peripheral devices may be placed in or connected to the harness. Alternatively or additionally, one or more of these peripheral devices may be integrated within the portable computer (i.e., a hand-held and/or wearable computer), if desired. It has also been suggested to provide a heads up display (HUD) worn by the wearable computer user to present the user or wearer with a visual interface. A wearable computer thereby provides portable computing power and memory to a user and, because a wearable computer is worn instead of carried by the user, the user""s hands are only required to manipulate a keyboard or other input device. Of course, a hand-held computer such as, for example, a PDA may be conveniently carried to a location within a plant within a user worn pouch or the like, or may be carried by hand, if desired. A user may then holster the hand-held computer or set it down using its integral stand, if one is provided, to permit the use of both hands.
While it has been previously suggested to use portable computers in environments such as office environments, it is not believed that neither a wearable computer nor a hand-held computer such as, for example, a PDA, has been incorporated in and used in a process control system to enhance the abilities of an operator or a technician to identify devices and to perform other functions within a process control environment. Also, most portable computers require the use of some sort of hand-manipulated input device, such as a keyboard or a twiddler. While these devices are typically ergonomically designed to be as least cumbersome as possible, these devices still require the use of a the wearer""s hands to input information or data. In a process control environment however, a technician typically needs to have both hands free in order to perform complex operations, such as calibrating and repairing devices, connecting devices within the process control system, etc.
A portable computer for use in a process environment having a process control system therein may include a housing adapted for portable operation, a processing unit disposed within the housing, a computer readable memory disposed within the housing and coupled to the processing unit and a display disposed within the housing and coupled to the processing unit. Additionally, the portable computer may include an input device that provides an input signal to the processing unit and a software routine that processes the input signal and provides information pertaining to the process control system via the display.
Alternatively or additionally, a portable computer for use in a process control system having a host system may include a housing adapted for hand-held operation, a processing unit disposed within the housing and a computer readable memory disposed within the housing and coupled to the processing unit. In addition, the portable computer may include a display disposed within the housing and coupled to the processing unit, a keypad disposed within the housing and coupled to the processing unit and a radio frequency transceiver disposed within the housing and coupled to the processing unit. The radio frequency transceiver may be adapted to communicate with the host system. The portable computer may also include a first software routine that processes a user input received from the keypad and sends a command to the host system via the radio frequency transceiver. Additionally, a second software routine may receive process information sent from the host system in response to the command via the radio frequency transceiver and display the received process information via the display.
Alternatively or additionally, a hand-held computer for interfacing with a process control system includes a housing adapted for hand-held operation, a processor disposed within the housing and a computer readable memory disposed within the housing and coupled to the processor. The hand-held computer may further include an electronic display disposed within the housing and coupled to the processor, a keypad disposed within the housing and coupled to the processing unit and a transceiver disposed within the housing and communicatively coupled to the processing unit. The transceiver may be adapted to communicate with a remotely situated processor and the hand-held computer may include a software routine that enables a user to interface with the process control system.